1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotCacheAccess.hpp"
26 #include "cds/aotArtifactFinder.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotLogging.hpp"
30 #include "cds/aotReferenceObjSupport.hpp"
31 #include "cds/archiveBuilder.hpp"
32 #include "cds/archiveHeapLoader.hpp"
33 #include "cds/archiveHeapWriter.hpp"
34 #include "cds/archiveUtils.hpp"
35 #include "cds/cdsConfig.hpp"
36 #include "cds/cdsEnumKlass.hpp"
37 #include "cds/cdsHeapVerifier.hpp"
38 #include "cds/heapShared.hpp"
39 #include "cds/metaspaceShared.hpp"
40 #include "classfile/classLoaderData.hpp"
41 #include "classfile/classLoaderExt.hpp"
42 #include "classfile/javaClasses.inline.hpp"
43 #include "classfile/modules.hpp"
44 #include "classfile/stringTable.hpp"
45 #include "classfile/symbolTable.hpp"
46 #include "classfile/systemDictionary.hpp"
47 #include "classfile/systemDictionaryShared.hpp"
48 #include "classfile/vmClasses.hpp"
49 #include "classfile/vmSymbols.hpp"
50 #include "gc/shared/collectedHeap.hpp"
51 #include "gc/shared/gcLocker.hpp"
52 #include "gc/shared/gcVMOperations.hpp"
53 #include "logging/log.hpp"
54 #include "logging/logStream.hpp"
55 #include "memory/iterator.inline.hpp"
56 #include "memory/resourceArea.hpp"
57 #include "memory/universe.hpp"
58 #include "oops/compressedOops.inline.hpp"
59 #include "oops/fieldStreams.inline.hpp"
60 #include "oops/objArrayOop.inline.hpp"
61 #include "oops/oop.inline.hpp"
62 #include "oops/typeArrayOop.inline.hpp"
63 #include "prims/jvmtiExport.hpp"
64 #include "runtime/arguments.hpp"
65 #include "runtime/fieldDescriptor.inline.hpp"
66 #include "runtime/init.hpp"
67 #include "runtime/javaCalls.hpp"
68 #include "runtime/mutexLocker.hpp"
69 #include "runtime/safepointVerifiers.hpp"
70 #include "utilities/bitMap.inline.hpp"
71 #include "utilities/copy.hpp"
72 #if INCLUDE_G1GC
73 #include "gc/g1/g1CollectedHeap.hpp"
74 #endif
75
76 #if INCLUDE_CDS_JAVA_HEAP
77
78 struct ArchivableStaticFieldInfo {
79 const char* klass_name;
80 const char* field_name;
81 InstanceKlass* klass;
82 int offset;
83 BasicType type;
84
85 ArchivableStaticFieldInfo(const char* k, const char* f)
86 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
87
88 bool valid() {
89 return klass_name != nullptr;
90 }
91 };
92
93 class HeapShared::ContextMark : public StackObj {
94 ResourceMark rm;
95 public:
96 ContextMark(const char* c) : rm{} {
97 _context->push(c);
98 }
99 ~ContextMark() {
100 _context->pop();
101 }
102 };
103
104 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
105
106 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
107 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
108 size_t HeapShared::_total_obj_count;
109 size_t HeapShared::_total_obj_size;
110
111 #ifndef PRODUCT
112 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
113 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
114 static const char* _test_class_name = nullptr;
115 static Klass* _test_class = nullptr;
116 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
117 #endif
118
119
120 //
121 // If you add new entries to the following tables, you should know what you're doing!
122 //
123
124 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
125 {"java/lang/Integer$IntegerCache", "archivedCache"},
126 {"java/lang/Long$LongCache", "archivedCache"},
127 {"java/lang/Byte$ByteCache", "archivedCache"},
128 {"java/lang/Short$ShortCache", "archivedCache"},
129 {"java/lang/Character$CharacterCache", "archivedCache"},
130 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
131 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
132 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
133 {"java/util/ImmutableCollections", "archivedObjects"},
134 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
135 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
136 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
137 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
138
139 #ifndef PRODUCT
140 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
141 #endif
142 {nullptr, nullptr},
143 };
144
145 // full module graph
146 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
147 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
148 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
149 {"java/lang/Module$ArchivedData", "archivedData"},
150 {nullptr, nullptr},
151 };
152
153 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
154 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
155 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
156 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
157 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments = nullptr;
158 int HeapShared::_root_segment_max_size_elems;
159 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
160 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
161
162 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
163 for (int i = 0; fields[i].valid(); i++) {
164 if (fields[i].klass == ik) {
165 return true;
166 }
167 }
168 return false;
169 }
170
171 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
172 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
173 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
174 }
175
176 unsigned HeapShared::oop_hash(oop const& p) {
177 // Do not call p->identity_hash() as that will update the
178 // object header.
179 return primitive_hash(cast_from_oop<intptr_t>(p));
180 }
181
182 static void reset_states(oop obj, TRAPS) {
183 Handle h_obj(THREAD, obj);
184 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
185 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
186 Symbol* method_sig = vmSymbols::void_method_signature();
187
188 while (klass != nullptr) {
189 Method* method = klass->find_method(method_name, method_sig);
190 if (method != nullptr) {
191 assert(method->is_private(), "must be");
192 if (log_is_enabled(Debug, aot)) {
193 ResourceMark rm(THREAD);
194 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
195 }
196 JavaValue result(T_VOID);
197 JavaCalls::call_special(&result, h_obj, klass,
198 method_name, method_sig, CHECK);
199 }
200 klass = klass->java_super();
201 }
202 }
203
204 void HeapShared::reset_archived_object_states(TRAPS) {
205 assert(CDSConfig::is_dumping_heap(), "dump-time only");
206 log_debug(aot)("Resetting platform loader");
207 reset_states(SystemDictionary::java_platform_loader(), CHECK);
208 log_debug(aot)("Resetting system loader");
209 reset_states(SystemDictionary::java_system_loader(), CHECK);
210
211 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
212 // directly used for class loading, but rather is used by the core library
213 // to keep track of resources, etc, loaded by the null class loader.
214 //
215 // Note, this object is non-null, and is not the same as
216 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
217 // which is null.
218 log_debug(aot)("Resetting boot loader");
219 JavaValue result(T_OBJECT);
220 JavaCalls::call_static(&result,
221 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
222 vmSymbols::bootLoader_name(),
223 vmSymbols::void_BuiltinClassLoader_signature(),
224 CHECK);
225 Handle boot_loader(THREAD, result.get_oop());
226 reset_states(boot_loader(), CHECK);
227 }
228
229 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
230
231 bool HeapShared::has_been_archived(oop obj) {
232 assert(CDSConfig::is_dumping_heap(), "dump-time only");
233 return archived_object_cache()->get(obj) != nullptr;
234 }
235
236 int HeapShared::append_root(oop obj) {
237 assert(CDSConfig::is_dumping_heap(), "dump-time only");
238 if (obj != nullptr) {
239 assert(has_been_archived(obj), "must be");
240 }
241 // No GC should happen since we aren't scanning _pending_roots.
242 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
243
244 OopHandle oh(Universe::vm_global(), obj);
245 return _pending_roots->append(oh);
246 }
247
248 objArrayOop HeapShared::root_segment(int segment_idx) {
249 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
250 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
251 } else {
252 assert(CDSConfig::is_using_archive(), "must be");
253 }
254
255 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
256 assert(segment != nullptr, "should have been initialized");
257 return segment;
258 }
259
260 inline unsigned int oop_handle_hash(const OopHandle& oh) {
261 oop o = oh.resolve();
262 if (o == nullptr) {
263 return 0;
264 } else {
265 return o->identity_hash();
266 }
267 }
268
269 inline bool oop_handle_equals(const OopHandle& a, const OopHandle& b) {
270 return a.resolve() == b.resolve();
271 }
272
273 class OrigToScratchObjectTable: public ResourceHashtable<OopHandle, OopHandle,
274 36137, // prime number
275 AnyObj::C_HEAP,
276 mtClassShared,
277 oop_handle_hash,
278 oop_handle_equals> {};
279
280 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
281
282 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
283 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
284 if (_orig_to_scratch_object_table == nullptr) {
285 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
286 }
287
288 OopHandle orig_h(Universe::vm_global(), orig_obj);
289 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
290 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
291 }
292
293 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
294 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
295 if (_orig_to_scratch_object_table != nullptr) {
296 OopHandle orig(&orig_obj);
297 OopHandle* v = _orig_to_scratch_object_table->get(orig);
298 if (v != nullptr) {
299 return v->resolve();
300 }
301 }
302 return nullptr;
303 }
304
305 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
306 // to Strings and MH oops.
307 //
308 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
309 // and are accssed vis AOTCacheAccess::get_archived_object(int).
310 struct PermanentOopInfo {
311 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
312 int _heap_offset; // Offset of the object from the bottom of the archived heap.
313 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
314 };
315
316 class PermanentOopTable: public ResourceHashtable<OopHandle, PermanentOopInfo,
317 36137, // prime number
318 AnyObj::C_HEAP,
319 mtClassShared,
320 oop_handle_hash,
321 oop_handle_equals> {};
322
323 static int _dumptime_permanent_oop_count = 0;
324 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
325 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
326
327 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
328 // so we can remember their offset (from the bottom of the archived heap).
329 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
330 assert_at_safepoint();
331 if (_dumptime_permanent_oop_table == nullptr) {
332 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
333 }
334
335 PermanentOopInfo info(-1, offset);
336 OopHandle oh(Universe::vm_global(), obj);
337 _dumptime_permanent_oop_table->put_when_absent(oh, info);
338 }
339
340 // A permanent index is assigned to an archived object ONLY when
341 // the AOT compiler calls this function.
342 int HeapShared::get_archived_object_permanent_index(oop obj) {
343 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
344
345 if (!CDSConfig::is_dumping_heap()) {
346 return -1; // Called by the Leyden old workflow
347 }
348 if (_dumptime_permanent_oop_table == nullptr) {
349 return -1;
350 }
351
352 if (_orig_to_scratch_object_table != nullptr) {
353 OopHandle orig(&obj);
354 OopHandle* v = _orig_to_scratch_object_table->get(orig);
355 if (v != nullptr) {
356 obj = v->resolve();
357 }
358 }
359
360 OopHandle tmp(&obj);
361 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
362 if (info == nullptr) {
363 return -1;
364 } else {
365 if (info->_index < 0) {
366 info->_index = _dumptime_permanent_oop_count++;
367 }
368 return info->_index;
369 }
370 }
371
372 oop HeapShared::get_archived_object(int permanent_index) {
373 assert(permanent_index >= 0, "sanity");
374 assert(ArchiveHeapLoader::is_in_use(), "sanity");
375 assert(_runtime_permanent_oops != nullptr, "sanity");
376
377 return _runtime_permanent_oops->at(permanent_index).resolve();
378 }
379
380 // Remember all archived heap objects that have a permanent index.
381 // table[i] = offset of oop whose permanent index is i.
382 void CachedCodeDirectoryInternal::dumptime_init_internal() {
383 const int count = _dumptime_permanent_oop_count;
384 if (count == 0) {
385 // Avoid confusing CDS code with zero-sized tables, just return.
386 log_info(cds)("No permanent oops");
387 _permanent_oop_count = count;
388 _permanent_oop_offsets = nullptr;
389 return;
390 }
391
392 int* table = (int*)AOTCacheAccess::allocate_aot_code_region(count * sizeof(int));
393 for (int i = 0; i < count; i++) {
394 table[count] = -1;
395 }
396 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
397 int index = info._index;
398 if (index >= 0) {
399 assert(index < count, "sanity");
400 table[index] = info._heap_offset;
401 }
402 return true; // continue
403 });
404
405 for (int i = 0; i < count; i++) {
406 assert(table[i] >= 0, "must be");
407 }
408
409 log_info(cds)("Dumped %d permanent oops", count);
410
411 _permanent_oop_count = count;
412 AOTCacheAccess::set_pointer(&_permanent_oop_offsets, table);
413 }
414
415 // This is called during the bootstrap of the production run, before any GC can happen.
416 // Record each permanent oop in a OopHandle for GC safety.
417 void CachedCodeDirectoryInternal::runtime_init_internal() {
418 int count = _permanent_oop_count;
419 int* table = _permanent_oop_offsets;
420 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
421 for (int i = 0; i < count; i++) {
422 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
423 OopHandle oh(Universe::vm_global(), obj);
424 _runtime_permanent_oops->append(oh);
425 }
426 };
427
428 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
429 assert(_root_segment_max_size_elems > 0, "sanity");
430
431 // Try to avoid divisions for the common case.
432 if (idx < _root_segment_max_size_elems) {
433 seg_idx = 0;
434 int_idx = idx;
435 } else {
436 seg_idx = idx / _root_segment_max_size_elems;
437 int_idx = idx % _root_segment_max_size_elems;
438 }
439
440 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
441 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
442 }
443
444 // Returns an objArray that contains all the roots of the archived objects
445 oop HeapShared::get_root(int index, bool clear) {
446 assert(index >= 0, "sanity");
447 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
448 assert(!_root_segments->is_empty(), "must have loaded shared heap");
449 int seg_idx, int_idx;
450 get_segment_indexes(index, seg_idx, int_idx);
451 oop result = root_segment(seg_idx)->obj_at(int_idx);
452 if (clear) {
453 clear_root(index);
454 }
455 return result;
456 }
457
458 void HeapShared::clear_root(int index) {
459 assert(index >= 0, "sanity");
460 assert(CDSConfig::is_using_archive(), "must be");
461 if (ArchiveHeapLoader::is_in_use()) {
462 int seg_idx, int_idx;
463 get_segment_indexes(index, seg_idx, int_idx);
464 if (log_is_enabled(Debug, aot, heap)) {
465 oop old = root_segment(seg_idx)->obj_at(int_idx);
466 log_debug(aot, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
467 }
468 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
469 }
470 }
471
472 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
473 assert(CDSConfig::is_dumping_heap(), "dump-time only");
474
475 assert(!obj->is_stackChunk(), "do not archive stack chunks");
476 if (has_been_archived(obj)) {
477 return true;
478 }
479
480 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
481 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
482 p2i(obj), obj->size());
483 debug_trace();
484 return false;
485 } else {
486 count_allocation(obj->size());
487 ArchiveHeapWriter::add_source_obj(obj);
488 CachedOopInfo info = make_cached_oop_info(obj, referrer);
489 archived_object_cache()->put_when_absent(obj, info);
490 archived_object_cache()->maybe_grow();
491 mark_native_pointers(obj);
492
493 Klass* k = obj->klass();
494 if (k->is_instance_klass()) {
495 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
496 // This ensures that during the production run, whenever Java code sees a cached object
497 // of type X, we know that X is already initialized. (see TODO comment below ...)
498
499 if (InstanceKlass::cast(k)->is_enum_subclass()
500 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
501 // we must store them as AOT-initialized.
502 || (subgraph_info == _dump_time_special_subgraph))
503 // TODO: we do this only for the special subgraph for now. Extending this to
504 // other subgraphs would require more refactoring of the core library (such as
505 // move some initialization logic into runtimeSetup()).
506 //
507 // For the other subgraphs, we have a weaker mechanism to ensure that
508 // all classes in a subgraph are initialized before the subgraph is programmatically
509 // returned from jdk.internal.misc.CDS::initializeFromArchive().
510 // See HeapShared::initialize_from_archived_subgraph().
511 {
512 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
513 }
514
515 if (java_lang_Class::is_instance(obj)) {
516 Klass* mirror_k = java_lang_Class::as_Klass(obj);
517 if (mirror_k != nullptr) {
518 AOTArtifactFinder::add_cached_class(mirror_k);
519 }
520 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
521 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
522 if (m != nullptr) {
523 InstanceKlass* method_holder = m->method_holder();
524 AOTArtifactFinder::add_cached_class(method_holder);
525 }
526 }
527 }
528
529 if (log_is_enabled(Debug, aot, heap)) {
530 ResourceMark rm;
531 LogTarget(Debug, aot, heap) log;
532 LogStream out(log);
533 out.print("Archived heap object " PTR_FORMAT " : %s ",
534 p2i(obj), obj->klass()->external_name());
535 if (java_lang_Class::is_instance(obj)) {
536 Klass* k = java_lang_Class::as_Klass(obj);
537 if (k != nullptr) {
538 out.print("%s", k->external_name());
539 } else {
540 out.print("primitive");
541 }
542 }
543 out.cr();
544 }
545
546 return true;
547 }
548 }
549
550 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
551 36137, // prime number
552 AnyObj::C_HEAP,
553 mtClassShared> {
554 public:
555 oop get_oop(MetaspaceObj* ptr) {
556 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
557 OopHandle* handle = get(ptr);
558 if (handle != nullptr) {
559 return handle->resolve();
560 } else {
561 return nullptr;
562 }
563 }
564 void set_oop(MetaspaceObj* ptr, oop o) {
565 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
566 OopHandle handle(Universe::vm_global(), o);
567 bool is_new = put(ptr, handle);
568 assert(is_new, "cannot set twice");
569 }
570 void remove_oop(MetaspaceObj* ptr) {
571 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
572 OopHandle* handle = get(ptr);
573 if (handle != nullptr) {
574 handle->release(Universe::vm_global());
575 remove(ptr);
576 }
577 }
578 };
579
580 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
581 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
582 _scratch_objects_table->set_oop(src, dest);
583 }
584 }
585
586 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
587 return (objArrayOop)_scratch_objects_table->get_oop(src);
588 }
589
590 void HeapShared::init_dumping() {
591 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
592 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
593 }
594
595 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
596 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
597 BasicType bt = (BasicType)i;
598 if (!is_reference_type(bt)) {
599 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
600 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
601 track_scratch_object(Universe::java_mirror(bt), m);
602 }
603 }
604 }
605
606 // Given java_mirror that represents a (primitive or reference) type T,
607 // return the "scratch" version that represents the same type T.
608 // Note that if java_mirror will be returned if it's already a
609 // scratch mirror.
610 //
611 // See java_lang_Class::create_scratch_mirror() for more info.
612 oop HeapShared::scratch_java_mirror(oop java_mirror) {
613 assert(java_lang_Class::is_instance(java_mirror), "must be");
614
615 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
616 BasicType bt = (BasicType)i;
617 if (!is_reference_type(bt)) {
618 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
619 return java_mirror;
620 }
621 }
622 }
623
624 if (java_lang_Class::is_primitive(java_mirror)) {
625 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
626 } else {
627 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
628 }
629 }
630
631 oop HeapShared::scratch_java_mirror(BasicType t) {
632 assert((uint)t < T_VOID+1, "range check");
633 assert(!is_reference_type(t), "sanity");
634 return _scratch_basic_type_mirrors[t].resolve();
635 }
636
637 oop HeapShared::scratch_java_mirror(Klass* k) {
638 return _scratch_objects_table->get_oop(k);
639 }
640
641 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
642 track_scratch_object(k->java_mirror(), mirror);
643 _scratch_objects_table->set_oop(k, mirror);
644 }
645
646 void HeapShared::remove_scratch_objects(Klass* k) {
647 // Klass is being deallocated. Java mirror can still be alive, and it should not
648 // point to dead klass. We need to break the link from mirror to the Klass.
649 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
650 oop mirror = _scratch_objects_table->get_oop(k);
651 if (mirror != nullptr) {
652 java_lang_Class::set_klass(mirror, nullptr);
653 }
654 _scratch_objects_table->remove_oop(k);
655 if (k->is_instance_klass()) {
656 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
657 }
658 if (mirror != nullptr) {
659 OopHandle tmp(&mirror);
660 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
661 if (v != nullptr) {
662 oop scratch_mirror = v->resolve();
663 java_lang_Class::set_klass(scratch_mirror, nullptr);
664 _orig_to_scratch_object_table->remove(tmp);
665 }
666 }
667 }
668
669 //TODO: we eventually want a more direct test for these kinds of things.
670 //For example the JVM could record some bit of context from the creation
671 //of the klass, such as who called the hidden class factory. Using
672 //string compares on names is fragile and will break as soon as somebody
673 //changes the names in the JDK code. See discussion in JDK-8342481 for
674 //related ideas about marking AOT-related classes.
675 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
676 return ik->is_hidden() &&
677 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
678 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
679 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
680 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
681 }
682
683 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
684 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
685 }
686
687 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
688 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
689 }
690
691 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
692 return CDSConfig::is_dumping_method_handles() &&
693 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
694 }
695
696
697 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
698 ik->set_has_aot_initialized_mirror();
699 if (AOTClassInitializer::is_runtime_setup_required(ik)) {
700 ik->set_is_runtime_setup_required();
701 }
702
703 oop orig_mirror = ik->java_mirror();
704 oop m = scratch_java_mirror(ik);
705 assert(ik->is_initialized(), "must be");
706
707 int nfields = 0;
708 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
709 if (fs.access_flags().is_static()) {
710 fieldDescriptor& fd = fs.field_descriptor();
711 int offset = fd.offset();
712 switch (fd.field_type()) {
713 case T_OBJECT:
714 case T_ARRAY:
715 {
716 oop field_obj = orig_mirror->obj_field(offset);
717 if (offset == java_lang_Class::reflection_data_offset()) {
718 // Class::reflectData use SoftReference, which cannot be archived. Set it
719 // to null and it will be recreated at runtime.
720 field_obj = nullptr;
721 }
722 m->obj_field_put(offset, field_obj);
723 if (field_obj != nullptr) {
724 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
725 assert(success, "sanity");
726 }
727 }
728 break;
729 case T_BOOLEAN:
730 m->bool_field_put(offset, orig_mirror->bool_field(offset));
731 break;
732 case T_BYTE:
733 m->byte_field_put(offset, orig_mirror->byte_field(offset));
734 break;
735 case T_SHORT:
736 m->short_field_put(offset, orig_mirror->short_field(offset));
737 break;
738 case T_CHAR:
739 m->char_field_put(offset, orig_mirror->char_field(offset));
740 break;
741 case T_INT:
742 m->int_field_put(offset, orig_mirror->int_field(offset));
743 break;
744 case T_LONG:
745 m->long_field_put(offset, orig_mirror->long_field(offset));
746 break;
747 case T_FLOAT:
748 m->float_field_put(offset, orig_mirror->float_field(offset));
749 break;
750 case T_DOUBLE:
751 m->double_field_put(offset, orig_mirror->double_field(offset));
752 break;
753 default:
754 ShouldNotReachHere();
755 }
756 nfields ++;
757 }
758 }
759
760 oop class_data = java_lang_Class::class_data(orig_mirror);
761 java_lang_Class::set_class_data(m, class_data);
762 if (class_data != nullptr) {
763 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
764 assert(success, "sanity");
765 }
766
767 if (log_is_enabled(Debug, aot, init)) {
768 ResourceMark rm;
769 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
770 ik->is_hidden() ? " (hidden)" : "",
771 ik->is_enum_subclass() ? " (enum)" : "");
772 }
773 }
774
775 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) {
776 // We need to retain the identity_hash, because it may have been used by some hashtables
777 // in the shared heap.
778 if (!orig_mirror->fast_no_hash_check()) {
779 intptr_t src_hash = orig_mirror->identity_hash();
780 if (UseCompactObjectHeaders) {
781 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
782 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
783 } else {
784 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
785 }
786 assert(scratch_m->mark().is_unlocked(), "sanity");
787
788 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
789 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
790 }
791 }
792
793 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
794 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
795 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
796 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
797 return HeapShared::scratch_resolved_references(src_ik->constants());
798 }
799 }
800 return nullptr;
801 }
802
803 void HeapShared::archive_strings() {
804 oop shared_strings_array = StringTable::init_shared_strings_array();
805 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
806 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
807 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
808 }
809
810 int HeapShared::archive_exception_instance(oop exception) {
811 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
812 assert(success, "sanity");
813 return append_root(exception);
814 }
815
816 void HeapShared::mark_native_pointers(oop orig_obj) {
817 if (java_lang_Class::is_instance(orig_obj)) {
818 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
819 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
820 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
821 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
822 }
823 }
824
825 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
826 CachedOopInfo* info = archived_object_cache()->get(src_obj);
827 assert(info != nullptr, "must be");
828 has_oop_pointers = info->has_oop_pointers();
829 has_native_pointers = info->has_native_pointers();
830 }
831
832 void HeapShared::set_has_native_pointers(oop src_obj) {
833 CachedOopInfo* info = archived_object_cache()->get(src_obj);
834 assert(info != nullptr, "must be");
835 info->set_has_native_pointers();
836 }
837
838 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
839 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
840 void HeapShared::start_scanning_for_oops() {
841 {
842 NoSafepointVerifier nsv;
843
844 // The special subgraph doesn't belong to any class. We use Object_klass() here just
845 // for convenience.
846 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
847 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
848
849 // Cache for recording where the archived objects are copied to
850 create_archived_object_cache();
851
852 if (UseCompressedOops || UseG1GC) {
853 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
854 UseCompressedOops ? p2i(CompressedOops::begin()) :
855 p2i((address)G1CollectedHeap::heap()->reserved().start()),
856 UseCompressedOops ? p2i(CompressedOops::end()) :
857 p2i((address)G1CollectedHeap::heap()->reserved().end()));
858 }
859
860 archive_subgraphs();
861 }
862
863 init_seen_objects_table();
864 Universe::archive_exception_instances();
865 }
866
867 void HeapShared::end_scanning_for_oops() {
868 archive_strings();
869 delete_seen_objects_table();
870 }
871
872 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
873 {
874 NoSafepointVerifier nsv;
875 if (!SkipArchiveHeapVerification) {
876 CDSHeapVerifier::verify();
877 }
878 check_special_subgraph_classes();
879 }
880
881 StringTable::write_shared_table();
882 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
883 for (int i = 0; i < _pending_roots->length(); i++) {
884 roots->append(_pending_roots->at(i).resolve());
885 }
886 ArchiveHeapWriter::write(roots, heap_info);
887 delete roots;
888
889 ArchiveBuilder::OtherROAllocMark mark;
890 write_subgraph_info_table();
891 }
892
893 void HeapShared::scan_java_mirror(oop orig_mirror) {
894 oop m = scratch_java_mirror(orig_mirror);
895 if (m != nullptr) { // nullptr if for custom class loader
896 copy_java_mirror_hashcode(orig_mirror, m);
897 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
898 assert(success, "sanity");
899 }
900 }
901
902 void HeapShared::scan_java_class(Klass* orig_k) {
903 scan_java_mirror(orig_k->java_mirror());
904
905 if (orig_k->is_instance_klass()) {
906 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
907 orig_ik->constants()->prepare_resolved_references_for_archiving();
908 objArrayOop rr = get_archived_resolved_references(orig_ik);
909 if (rr != nullptr) {
910 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
911 assert(success, "must be");
912 }
913 }
914 }
915
916 void HeapShared::archive_subgraphs() {
917 assert(CDSConfig::is_dumping_heap(), "must be");
918
919 archive_object_subgraphs(archive_subgraph_entry_fields,
920 false /* is_full_module_graph */);
921
922 if (CDSConfig::is_dumping_full_module_graph()) {
923 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
924 true /* is_full_module_graph */);
925 Modules::verify_archived_modules();
926 }
927 }
928
929 //
930 // Subgraph archiving support
931 //
932 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
933 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
934
935 // Get the subgraph_info for Klass k. A new subgraph_info is created if
936 // there is no existing one for k. The subgraph_info records the "buffered"
937 // address of the class.
938 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
939 assert(CDSConfig::is_dumping_heap(), "dump time only");
940 bool created;
941 KlassSubGraphInfo* info =
942 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
943 &created);
944 assert(created, "must not initialize twice");
945 return info;
946 }
947
948 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
949 assert(CDSConfig::is_dumping_heap(), "dump time only");
950 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
951 assert(info != nullptr, "must have been initialized");
952 return info;
953 }
954
955 // Add an entry field to the current KlassSubGraphInfo.
956 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
957 assert(CDSConfig::is_dumping_heap(), "dump time only");
958 if (_subgraph_entry_fields == nullptr) {
959 _subgraph_entry_fields =
960 new (mtClass) GrowableArray<int>(10, mtClass);
961 }
962 _subgraph_entry_fields->append(static_field_offset);
963 _subgraph_entry_fields->append(HeapShared::append_root(v));
964 }
965
966 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
967 // Only objects of boot classes can be included in sub-graph.
968 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
969 assert(CDSConfig::is_dumping_heap(), "dump time only");
970
971 if (_subgraph_object_klasses == nullptr) {
972 _subgraph_object_klasses =
973 new (mtClass) GrowableArray<Klass*>(50, mtClass);
974 }
975
976 if (_k == orig_k) {
977 // Don't add the Klass containing the sub-graph to it's own klass
978 // initialization list.
979 return;
980 }
981
982 if (orig_k->is_instance_klass()) {
983 #ifdef ASSERT
984 InstanceKlass* ik = InstanceKlass::cast(orig_k);
985 if (CDSConfig::is_dumping_method_handles()) {
986 // -XX:AOTInitTestClass must be used carefully in regression tests to
987 // include only classes that are safe to aot-initialize.
988 assert(ik->class_loader() == nullptr ||
989 HeapShared::is_lambda_proxy_klass(ik) ||
990 AOTClassInitializer::has_test_class(),
991 "we can archive only instances of boot classes or lambda proxy classes");
992 } else {
993 assert(ik->class_loader() == nullptr, "must be boot class");
994 }
995 #endif
996 // vmClasses::xxx_klass() are not updated, need to check
997 // the original Klass*
998 if (orig_k == vmClasses::String_klass() ||
999 orig_k == vmClasses::Object_klass()) {
1000 // Initialized early during VM initialization. No need to be added
1001 // to the sub-graph object class list.
1002 return;
1003 }
1004 check_allowed_klass(InstanceKlass::cast(orig_k));
1005 } else if (orig_k->is_objArray_klass()) {
1006 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1007 if (abk->is_instance_klass()) {
1008 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1009 "must be boot class");
1010 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1011 }
1012 if (orig_k == Universe::objectArrayKlass()) {
1013 // Initialized early during Universe::genesis. No need to be added
1014 // to the list.
1015 return;
1016 }
1017 } else {
1018 assert(orig_k->is_typeArray_klass(), "must be");
1019 // Primitive type arrays are created early during Universe::genesis.
1020 return;
1021 }
1022
1023 if (log_is_enabled(Debug, aot, heap)) {
1024 if (!_subgraph_object_klasses->contains(orig_k)) {
1025 ResourceMark rm;
1026 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1027 }
1028 }
1029
1030 _subgraph_object_klasses->append_if_missing(orig_k);
1031 _has_non_early_klasses |= is_non_early_klass(orig_k);
1032 }
1033
1034 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1035 #ifndef PRODUCT
1036 if (AOTClassInitializer::has_test_class()) {
1037 // The tests can cache arbitrary types of objects.
1038 return;
1039 }
1040 #endif
1041
1042 if (ik->module()->name() == vmSymbols::java_base()) {
1043 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1044 return;
1045 }
1046
1047 const char* lambda_msg = "";
1048 if (CDSConfig::is_dumping_method_handles()) {
1049 lambda_msg = ", or a lambda proxy class";
1050 if (HeapShared::is_lambda_proxy_klass(ik) &&
1051 (ik->class_loader() == nullptr ||
1052 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1053 ik->class_loader() == SystemDictionary::java_system_loader())) {
1054 return;
1055 }
1056 }
1057
1058 #ifndef PRODUCT
1059 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1060 // This class is loaded by ArchiveHeapTestClass
1061 return;
1062 }
1063 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1064 #else
1065 const char* testcls_msg = "";
1066 #endif
1067
1068 ResourceMark rm;
1069 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1070 ik->external_name(), lambda_msg, testcls_msg);
1071 MetaspaceShared::unrecoverable_writing_error();
1072 }
1073
1074 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1075 if (k->is_objArray_klass()) {
1076 k = ObjArrayKlass::cast(k)->bottom_klass();
1077 }
1078 if (k->is_instance_klass()) {
1079 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1080 ResourceMark rm;
1081 log_info(aot, heap)("non-early: %s", k->external_name());
1082 return true;
1083 } else {
1084 return false;
1085 }
1086 } else {
1087 return false;
1088 }
1089 }
1090
1091 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1092 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1093 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1094 _entry_field_records = nullptr;
1095 _subgraph_object_klasses = nullptr;
1096 _is_full_module_graph = info->is_full_module_graph();
1097
1098 if (_is_full_module_graph) {
1099 // Consider all classes referenced by the full module graph as early -- we will be
1100 // allocating objects of these classes during JVMTI early phase, so they cannot
1101 // be processed by (non-early) JVMTI ClassFileLoadHook
1102 _has_non_early_klasses = false;
1103 } else {
1104 _has_non_early_klasses = info->has_non_early_klasses();
1105 }
1106
1107 if (_has_non_early_klasses) {
1108 ResourceMark rm;
1109 log_info(aot, heap)(
1110 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1111 _k->external_name());
1112 }
1113
1114 // populate the entry fields
1115 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1116 if (entry_fields != nullptr) {
1117 int num_entry_fields = entry_fields->length();
1118 assert(num_entry_fields % 2 == 0, "sanity");
1119 _entry_field_records =
1120 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1121 for (int i = 0 ; i < num_entry_fields; i++) {
1122 _entry_field_records->at_put(i, entry_fields->at(i));
1123 }
1124 }
1125
1126 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1127 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1128 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1129 if (recorded_klasses != nullptr) {
1130 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1131 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1132 // that are not aot-inited.
1133 int num_to_copy = 0;
1134 for (int i = 0; i < recorded_klasses->length(); i++) {
1135 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1136 if (!subgraph_k->has_aot_initialized_mirror()) {
1137 num_to_copy ++;
1138 }
1139 }
1140
1141 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1142 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1143 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1144 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1145 if (subgraph_k->has_aot_initialized_mirror()) {
1146 continue;
1147 }
1148 if (log_is_enabled(Info, aot, heap)) {
1149 ResourceMark rm;
1150 const char* owner_name = is_special ? "<special>" : _k->external_name();
1151 if (subgraph_k->is_instance_klass()) {
1152 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1153 }
1154 log_info(aot, heap)(
1155 "Archived object klass %s (%2d) => %s",
1156 owner_name, n, subgraph_k->external_name());
1157 }
1158 _subgraph_object_klasses->at_put(n, subgraph_k);
1159 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1160 n++;
1161 }
1162 }
1163
1164 ArchivePtrMarker::mark_pointer(&_k);
1165 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1166 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1167 }
1168
1169 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1170 CompactHashtableWriter* _writer;
1171 public:
1172 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1173
1174 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1175 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1176 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1177 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1178 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1179 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1180 _writer->add(hash, delta);
1181 }
1182 return true; // keep on iterating
1183 }
1184 };
1185
1186 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1187 ArchivedKlassSubGraphInfoRecord* record =
1188 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1189 record->init(info);
1190 if (info == _dump_time_special_subgraph) {
1191 _run_time_special_subgraph = record;
1192 }
1193 return record;
1194 }
1195
1196 // Build the records of archived subgraph infos, which include:
1197 // - Entry points to all subgraphs from the containing class mirror. The entry
1198 // points are static fields in the mirror. For each entry point, the field
1199 // offset, and value are recorded in the sub-graph
1200 // info. The value is stored back to the corresponding field at runtime.
1201 // - A list of klasses that need to be loaded/initialized before archived
1202 // java object sub-graph can be accessed at runtime.
1203 void HeapShared::write_subgraph_info_table() {
1204 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1205 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1206 CompactHashtableStats stats;
1207
1208 _run_time_subgraph_info_table.reset();
1209
1210 CompactHashtableWriter writer(d_table->_count, &stats);
1211 CopyKlassSubGraphInfoToArchive copy(&writer);
1212 d_table->iterate(©);
1213 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1214
1215 #ifndef PRODUCT
1216 if (ArchiveHeapTestClass != nullptr) {
1217 size_t len = strlen(ArchiveHeapTestClass) + 1;
1218 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1219 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1220 _archived_ArchiveHeapTestClass = array;
1221 }
1222 #endif
1223 if (log_is_enabled(Info, aot, heap)) {
1224 print_stats();
1225 }
1226 }
1227
1228 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1229 assert(segment_oop != nullptr, "must be");
1230 assert(ArchiveHeapLoader::is_in_use(), "must be");
1231 if (_root_segments == nullptr) {
1232 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1233 }
1234 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1235 }
1236
1237 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1238 _root_segment_max_size_elems = max_size_elems;
1239 }
1240
1241 void HeapShared::serialize_tables(SerializeClosure* soc) {
1242
1243 #ifndef PRODUCT
1244 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1245 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1246 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1247 setup_test_class(_test_class_name);
1248 }
1249 #endif
1250
1251 _run_time_subgraph_info_table.serialize_header(soc);
1252 soc->do_ptr(&_run_time_special_subgraph);
1253 }
1254
1255 static void verify_the_heap(Klass* k, const char* which) {
1256 if (VerifyArchivedFields > 0) {
1257 ResourceMark rm;
1258 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1259 which, k->external_name());
1260
1261 VM_Verify verify_op;
1262 VMThread::execute(&verify_op);
1263
1264 if (VerifyArchivedFields > 1 && is_init_completed()) {
1265 // At this time, the oop->klass() of some archived objects in the heap may not
1266 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1267 // have enough information (object size, oop maps, etc) so that a GC can be safely
1268 // performed.
1269 //
1270 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1271 // to check for GC safety.
1272 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1273 which, k->external_name());
1274 FlagSetting fs1(VerifyBeforeGC, true);
1275 FlagSetting fs2(VerifyDuringGC, true);
1276 FlagSetting fs3(VerifyAfterGC, true);
1277 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1278 }
1279 }
1280 }
1281
1282 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1283 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1284 //
1285 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1286 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1287 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1288 void HeapShared::resolve_classes(JavaThread* current) {
1289 assert(CDSConfig::is_using_archive(), "runtime only!");
1290 if (!ArchiveHeapLoader::is_in_use()) {
1291 return; // nothing to do
1292 }
1293
1294 if (!CDSConfig::is_using_aot_linked_classes()) {
1295 assert( _run_time_special_subgraph != nullptr, "must be");
1296 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1297 if (klasses != nullptr) {
1298 for (int i = 0; i < klasses->length(); i++) {
1299 Klass* k = klasses->at(i);
1300 ExceptionMark em(current); // no exception can happen here
1301 resolve_or_init(k, /*do_init*/false, current);
1302 }
1303 }
1304 }
1305
1306 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1307 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1308 }
1309
1310 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1311 for (int i = 0; fields[i].valid(); i++) {
1312 ArchivableStaticFieldInfo* info = &fields[i];
1313 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1314 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1315 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1316 resolve_classes_for_subgraph_of(current, k);
1317 }
1318 }
1319
1320 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1321 JavaThread* THREAD = current;
1322 ExceptionMark em(THREAD);
1323 const ArchivedKlassSubGraphInfoRecord* record =
1324 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1325 if (HAS_PENDING_EXCEPTION) {
1326 CLEAR_PENDING_EXCEPTION;
1327 }
1328 if (record == nullptr) {
1329 clear_archived_roots_of(k);
1330 }
1331 }
1332
1333 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1334 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1335 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1336 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1337 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1338 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1339 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1340 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1341 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1342 }
1343 }
1344
1345 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1346 // - interned strings
1347 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1348 // - ConstantPool::resolved_references()
1349 // - Universe::<xxx>_exception_instance()
1350 //
1351 // For example, if this enum class is initialized at AOT cache assembly time:
1352 //
1353 // enum Fruit {
1354 // APPLE, ORANGE, BANANA;
1355 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1356 // }
1357 //
1358 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1359 // should be initialized before any Java code can access the Fruit class. Note that
1360 // HashSet itself doesn't necessary need to be an aot-initialized class.
1361 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1362 if (!ArchiveHeapLoader::is_in_use()) {
1363 return;
1364 }
1365
1366 assert( _run_time_special_subgraph != nullptr, "must be");
1367 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1368 if (klasses != nullptr) {
1369 for (int pass = 0; pass < 2; pass ++) {
1370 for (int i = 0; i < klasses->length(); i++) {
1371 Klass* k = klasses->at(i);
1372 if (k->class_loader_data() == nullptr) {
1373 // This class is not yet loaded. We will initialize it in a later phase.
1374 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1375 // but k is part of AOTLinkedClassCategory::BOOT2.
1376 continue;
1377 }
1378 if (k->class_loader() == class_loader()) {
1379 if (pass == 0) {
1380 if (k->is_instance_klass()) {
1381 InstanceKlass::cast(k)->link_class(CHECK);
1382 }
1383 } else {
1384 resolve_or_init(k, /*do_init*/true, CHECK);
1385 }
1386 }
1387 }
1388 }
1389 }
1390 }
1391
1392 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1393 JavaThread* THREAD = current;
1394 if (!ArchiveHeapLoader::is_in_use()) {
1395 return; // nothing to do
1396 }
1397
1398 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1399 !CDSConfig::is_using_optimized_module_handling() &&
1400 // archive was created with --module-path
1401 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1402 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1403 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1404 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1405 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1406 AOTClassLocationConfig::runtime()->num_module_paths());
1407 return;
1408 }
1409
1410 ExceptionMark em(THREAD);
1411 const ArchivedKlassSubGraphInfoRecord* record =
1412 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1413
1414 if (HAS_PENDING_EXCEPTION) {
1415 CLEAR_PENDING_EXCEPTION;
1416 // None of the field value will be set if there was an exception when initializing the classes.
1417 // The java code will not see any of the archived objects in the
1418 // subgraphs referenced from k in this case.
1419 return;
1420 }
1421
1422 if (record != nullptr) {
1423 init_archived_fields_for(k, record);
1424 }
1425 }
1426
1427 const ArchivedKlassSubGraphInfoRecord*
1428 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1429 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1430
1431 if (!k->is_shared()) {
1432 return nullptr;
1433 }
1434 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1435 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1436
1437 #ifndef PRODUCT
1438 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1439 _test_class = k;
1440 _test_class_record = record;
1441 }
1442 #endif
1443
1444 // Initialize from archived data. Currently this is done only
1445 // during VM initialization time. No lock is needed.
1446 if (record == nullptr) {
1447 if (log_is_enabled(Info, aot, heap)) {
1448 ResourceMark rm(THREAD);
1449 log_info(aot, heap)("subgraph %s is not recorded",
1450 k->external_name());
1451 }
1452 return nullptr;
1453 } else {
1454 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1455 if (log_is_enabled(Info, aot, heap)) {
1456 ResourceMark rm(THREAD);
1457 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1458 k->external_name());
1459 }
1460 return nullptr;
1461 }
1462
1463 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1464 if (log_is_enabled(Info, aot, heap)) {
1465 ResourceMark rm(THREAD);
1466 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1467 k->external_name());
1468 }
1469 return nullptr;
1470 }
1471
1472 if (log_is_enabled(Info, aot, heap)) {
1473 ResourceMark rm;
1474 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1475 }
1476
1477 resolve_or_init(k, do_init, CHECK_NULL);
1478
1479 // Load/link/initialize the klasses of the objects in the subgraph.
1480 // nullptr class loader is used.
1481 Array<Klass*>* klasses = record->subgraph_object_klasses();
1482 if (klasses != nullptr) {
1483 for (int i = 0; i < klasses->length(); i++) {
1484 Klass* klass = klasses->at(i);
1485 if (!klass->is_shared()) {
1486 return nullptr;
1487 }
1488 resolve_or_init(klass, do_init, CHECK_NULL);
1489 }
1490 }
1491 }
1492
1493 return record;
1494 }
1495
1496 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1497 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1498 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1499 if (k == nullptr) {
1500 return;
1501 }
1502 assert(k->defined_by_boot_loader(), "sanity");
1503 resolve_or_init(k, false, CHECK);
1504 if (do_init) {
1505 resolve_or_init(k, true, CHECK);
1506 }
1507 }
1508
1509 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1510 if (!do_init) {
1511 if (k->class_loader_data() == nullptr) {
1512 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1513 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1514 }
1515 } else {
1516 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1517 if (k->is_instance_klass()) {
1518 InstanceKlass* ik = InstanceKlass::cast(k);
1519 ik->initialize(CHECK);
1520 } else if (k->is_objArray_klass()) {
1521 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1522 oak->initialize(CHECK);
1523 }
1524 }
1525 }
1526
1527 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1528 verify_the_heap(k, "before");
1529
1530 // Load the subgraph entry fields from the record and store them back to
1531 // the corresponding fields within the mirror.
1532 oop m = k->java_mirror();
1533 Array<int>* entry_field_records = record->entry_field_records();
1534 if (entry_field_records != nullptr) {
1535 int efr_len = entry_field_records->length();
1536 assert(efr_len % 2 == 0, "sanity");
1537 for (int i = 0; i < efr_len; i += 2) {
1538 int field_offset = entry_field_records->at(i);
1539 int root_index = entry_field_records->at(i+1);
1540 oop v = get_root(root_index, /*clear=*/true);
1541 if (k->has_aot_initialized_mirror()) {
1542 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1543 } else {
1544 m->obj_field_put(field_offset, v);
1545 }
1546 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1547 }
1548
1549 // Done. Java code can see the archived sub-graphs referenced from k's
1550 // mirror after this point.
1551 if (log_is_enabled(Info, aot, heap)) {
1552 ResourceMark rm;
1553 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1554 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1555 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1556 }
1557 }
1558
1559 verify_the_heap(k, "after ");
1560 }
1561
1562 void HeapShared::clear_archived_roots_of(Klass* k) {
1563 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1564 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1565 if (record != nullptr) {
1566 Array<int>* entry_field_records = record->entry_field_records();
1567 if (entry_field_records != nullptr) {
1568 int efr_len = entry_field_records->length();
1569 assert(efr_len % 2 == 0, "sanity");
1570 for (int i = 0; i < efr_len; i += 2) {
1571 int root_index = entry_field_records->at(i+1);
1572 clear_root(root_index);
1573 }
1574 }
1575 }
1576 }
1577
1578 // Push all oop fields (or oop array elemenets in case of an objArray) in
1579 // _referencing_obj onto the _stack.
1580 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1581 PendingOopStack* _stack;
1582 GrowableArray<oop> _found_oop_fields;
1583 int _level;
1584 bool _record_klasses_only;
1585 KlassSubGraphInfo* _subgraph_info;
1586 oop _referencing_obj;
1587 bool _is_java_lang_ref;
1588 public:
1589 OopFieldPusher(PendingOopStack* stack,
1590 int level,
1591 bool record_klasses_only,
1592 KlassSubGraphInfo* subgraph_info,
1593 oop orig) :
1594 _stack(stack),
1595 _found_oop_fields(),
1596 _level(level),
1597 _record_klasses_only(record_klasses_only),
1598 _subgraph_info(subgraph_info),
1599 _referencing_obj(orig) {
1600 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1601 }
1602 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1603 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1604
1605 ~OopFieldPusher() {
1606 while (_found_oop_fields.length() > 0) {
1607 // This produces the exact same traversal order as the previous version
1608 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1609 // walking the oop fields in _referencing_obj by ascending field offsets.
1610 oop obj = _found_oop_fields.pop();
1611 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1612 }
1613 }
1614
1615 protected:
1616 template <class T> void do_oop_work(T *p) {
1617 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1618 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1619 if (!CompressedOops::is_null(obj)) {
1620 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1621 // Do not follow these fields. They will be cleared to null.
1622 return;
1623 }
1624
1625 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1626 ResourceMark rm;
1627 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1628 _referencing_obj->klass()->external_name(), field_offset,
1629 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1630 if (log_is_enabled(Trace, aot, heap)) {
1631 LogTarget(Trace, aot, heap) log;
1632 LogStream out(log);
1633 obj->print_on(&out);
1634 }
1635 }
1636
1637 _found_oop_fields.push(obj);
1638 }
1639 }
1640
1641 public:
1642 oop referencing_obj() { return _referencing_obj; }
1643 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1644 };
1645
1646 // Checks if an oop has any non-null oop fields
1647 class PointsToOopsChecker : public BasicOopIterateClosure {
1648 bool _result;
1649
1650 template <class T> void check(T *p) {
1651 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1652 }
1653
1654 public:
1655 PointsToOopsChecker() : _result(false) {}
1656 void do_oop(narrowOop *p) { check(p); }
1657 void do_oop( oop *p) { check(p); }
1658 bool result() { return _result; }
1659 };
1660
1661 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1662 PointsToOopsChecker points_to_oops_checker;
1663 obj->oop_iterate(&points_to_oops_checker);
1664 return CachedOopInfo(referrer, points_to_oops_checker.result());
1665 }
1666
1667 void HeapShared::init_box_classes(TRAPS) {
1668 if (ArchiveHeapLoader::is_in_use()) {
1669 vmClasses::Boolean_klass()->initialize(CHECK);
1670 vmClasses::Character_klass()->initialize(CHECK);
1671 vmClasses::Float_klass()->initialize(CHECK);
1672 vmClasses::Double_klass()->initialize(CHECK);
1673 vmClasses::Byte_klass()->initialize(CHECK);
1674 vmClasses::Short_klass()->initialize(CHECK);
1675 vmClasses::Integer_klass()->initialize(CHECK);
1676 vmClasses::Long_klass()->initialize(CHECK);
1677 vmClasses::Void_klass()->initialize(CHECK);
1678 }
1679 }
1680
1681 void HeapShared::exit_on_error() {
1682 if (_context != nullptr) {
1683 ResourceMark rm;
1684 LogStream ls(Log(cds, heap)::error());
1685 ls.print_cr("Context");
1686 for (int i = 0; i < _context->length(); i++) {
1687 const char* s = _context->at(i);
1688 ls.print_cr("- %s", s);
1689 }
1690 }
1691 debug_trace();
1692 MetaspaceShared::unrecoverable_writing_error();
1693 }
1694
1695 // (1) If orig_obj has not been archived yet, archive it.
1696 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1697 // trace all objects that are reachable from it, and make sure these objects are archived.
1698 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1699 // were already archived when this function is called)
1700 bool HeapShared::archive_reachable_objects_from(int level,
1701 KlassSubGraphInfo* subgraph_info,
1702 oop orig_obj) {
1703 assert(orig_obj != nullptr, "must be");
1704 PendingOopStack stack;
1705 stack.push(PendingOop(orig_obj, nullptr, level));
1706
1707 while (stack.length() > 0) {
1708 PendingOop po = stack.pop();
1709 _object_being_archived = po;
1710 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1711 _object_being_archived = PendingOop();
1712
1713 if (!status) {
1714 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1715 // as the Java code will take care of initializing this field dynamically.
1716 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1717 return false;
1718 }
1719 }
1720
1721 return true;
1722 }
1723
1724 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1725 oop orig_obj, oop referrer) {
1726 assert(orig_obj != nullptr, "must be");
1727 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1728 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1729 // If you get an error here, you probably made a change in the JDK library that has added
1730 // these objects that are referenced (directly or indirectly) by static fields.
1731 ResourceMark rm;
1732 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1733 debug_trace();
1734 MetaspaceShared::unrecoverable_writing_error();
1735 }
1736
1737 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1738 ResourceMark rm;
1739 LogTarget(Debug, aot, heap) log;
1740 LogStream out(log);
1741 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1742 Klass* k = java_lang_Class::as_Klass(orig_obj);
1743 if (k != nullptr) {
1744 out.print("%s", k->external_name());
1745 } else {
1746 out.print("primitive");
1747 }
1748 out.print_cr("; scratch mirror = " PTR_FORMAT,
1749 p2i(scratch_java_mirror(orig_obj)));
1750 }
1751
1752 if (CDSConfig::is_initing_classes_at_dump_time()) {
1753 if (java_lang_Class::is_instance(orig_obj)) {
1754 orig_obj = scratch_java_mirror(orig_obj);
1755 assert(orig_obj != nullptr, "must be archived");
1756 }
1757 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1758 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1759 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1760 // very early by HeapShared::init_box_classes().
1761 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1762 || java_lang_Class::is_primitive(orig_obj)
1763 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1764 || orig_obj == vmClasses::Character_klass()->java_mirror()
1765 || orig_obj == vmClasses::Float_klass()->java_mirror()
1766 || orig_obj == vmClasses::Double_klass()->java_mirror()
1767 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1768 || orig_obj == vmClasses::Short_klass()->java_mirror()
1769 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1770 || orig_obj == vmClasses::Long_klass()->java_mirror()
1771 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1772 orig_obj = scratch_java_mirror(orig_obj);
1773 assert(orig_obj != nullptr, "must be archived");
1774 } else {
1775 // If you get an error here, you probably made a change in the JDK library that has added a Class
1776 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1777 // defined at the top of this file.
1778 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1779 debug_trace();
1780 MetaspaceShared::unrecoverable_writing_error();
1781 }
1782 }
1783
1784 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1785 // orig_obj has already been archived and traced. Nothing more to do.
1786 return true;
1787 } else {
1788 set_has_been_seen_during_subgraph_recording(orig_obj);
1789 }
1790
1791 bool already_archived = has_been_archived(orig_obj);
1792 bool record_klasses_only = already_archived;
1793 if (!already_archived) {
1794 ++_num_new_archived_objs;
1795 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1796 // Skip archiving the sub-graph referenced from the current entry field.
1797 ResourceMark rm;
1798 log_error(aot, heap)(
1799 "Cannot archive the sub-graph referenced from %s object ("
1800 PTR_FORMAT ") size %zu, skipped.",
1801 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1802 if (level == 1) {
1803 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1804 // as the Java code will take care of initializing this field dynamically.
1805 return false;
1806 } else {
1807 // We don't know how to handle an object that has been archived, but some of its reachable
1808 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1809 // we have a real use case.
1810 exit_on_error();
1811 }
1812 }
1813 }
1814
1815 Klass *orig_k = orig_obj->klass();
1816 subgraph_info->add_subgraph_object_klass(orig_k);
1817
1818 {
1819 // Find all the oops that are referenced by orig_obj, push them onto the stack
1820 // so we can work on them next.
1821 ResourceMark rm;
1822 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1823 orig_obj->oop_iterate(&pusher);
1824 }
1825
1826 if (CDSConfig::is_initing_classes_at_dump_time()) {
1827 // The enum klasses are archived with aot-initialized mirror.
1828 // See AOTClassInitializer::can_archive_initialized_mirror().
1829 } else {
1830 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1831 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1832 }
1833 }
1834
1835 return true;
1836 }
1837
1838 //
1839 // Start from the given static field in a java mirror and archive the
1840 // complete sub-graph of java heap objects that are reached directly
1841 // or indirectly from the starting object by following references.
1842 // Sub-graph archiving restrictions (current):
1843 //
1844 // - All classes of objects in the archived sub-graph (including the
1845 // entry class) must be boot class only.
1846 // - No java.lang.Class instance (java mirror) can be included inside
1847 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1848 //
1849 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1850 //
1851 // 1) Java object sub-graph archiving starts from a given static field
1852 // within a Class instance (java mirror). If the static field is a
1853 // reference field and points to a non-null java object, proceed to
1854 // the next step.
1855 //
1856 // 2) Archives the referenced java object. If an archived copy of the
1857 // current object already exists, updates the pointer in the archived
1858 // copy of the referencing object to point to the current archived object.
1859 // Otherwise, proceed to the next step.
1860 //
1861 // 3) Follows all references within the current java object and recursively
1862 // archive the sub-graph of objects starting from each reference.
1863 //
1864 // 4) Updates the pointer in the archived copy of referencing object to
1865 // point to the current archived object.
1866 //
1867 // 5) The Klass of the current java object is added to the list of Klasses
1868 // for loading and initializing before any object in the archived graph can
1869 // be accessed at runtime.
1870 //
1871 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1872 const char* klass_name,
1873 int field_offset,
1874 const char* field_name) {
1875 assert(CDSConfig::is_dumping_heap(), "dump time only");
1876 assert(k->defined_by_boot_loader(), "must be boot class");
1877
1878 oop m = k->java_mirror();
1879
1880 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1881 oop f = m->obj_field(field_offset);
1882
1883 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1884
1885 if (!CompressedOops::is_null(f)) {
1886 if (log_is_enabled(Trace, aot, heap)) {
1887 LogTarget(Trace, aot, heap) log;
1888 LogStream out(log);
1889 f->print_on(&out);
1890 }
1891
1892 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1893 if (!success) {
1894 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1895 klass_name, field_name);
1896 } else {
1897 // Note: the field value is not preserved in the archived mirror.
1898 // Record the field as a new subGraph entry point. The recorded
1899 // information is restored from the archive at runtime.
1900 subgraph_info->add_subgraph_entry_field(field_offset, f);
1901 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1902 }
1903 } else {
1904 // The field contains null, we still need to record the entry point,
1905 // so it can be restored at runtime.
1906 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1907 }
1908 }
1909
1910 #ifndef PRODUCT
1911 class VerifySharedOopClosure: public BasicOopIterateClosure {
1912 public:
1913 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1914 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1915
1916 protected:
1917 template <class T> void do_oop_work(T *p) {
1918 oop obj = RawAccess<>::oop_load(p);
1919 if (!CompressedOops::is_null(obj)) {
1920 HeapShared::verify_reachable_objects_from(obj);
1921 }
1922 }
1923 };
1924
1925 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1926 assert(CDSConfig::is_dumping_heap(), "dump time only");
1927 assert(k->defined_by_boot_loader(), "must be boot class");
1928
1929 oop m = k->java_mirror();
1930 oop f = m->obj_field(field_offset);
1931 if (!CompressedOops::is_null(f)) {
1932 verify_subgraph_from(f);
1933 }
1934 }
1935
1936 void HeapShared::verify_subgraph_from(oop orig_obj) {
1937 if (!has_been_archived(orig_obj)) {
1938 // It's OK for the root of a subgraph to be not archived. See comments in
1939 // archive_reachable_objects_from().
1940 return;
1941 }
1942
1943 // Verify that all objects reachable from orig_obj are archived.
1944 init_seen_objects_table();
1945 verify_reachable_objects_from(orig_obj);
1946 delete_seen_objects_table();
1947 }
1948
1949 void HeapShared::verify_reachable_objects_from(oop obj) {
1950 _num_total_verifications ++;
1951 if (java_lang_Class::is_instance(obj)) {
1952 obj = scratch_java_mirror(obj);
1953 assert(obj != nullptr, "must be");
1954 }
1955 if (!has_been_seen_during_subgraph_recording(obj)) {
1956 set_has_been_seen_during_subgraph_recording(obj);
1957 assert(has_been_archived(obj), "must be");
1958 VerifySharedOopClosure walker;
1959 obj->oop_iterate(&walker);
1960 }
1961 }
1962 #endif
1963
1964 void HeapShared::check_special_subgraph_classes() {
1965 if (CDSConfig::is_initing_classes_at_dump_time()) {
1966 // We can have aot-initialized classes (such as Enums) that can reference objects
1967 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
1968 // aot-initialize classes that are "safe".
1969 //
1970 // TODO: we need an automatic tool that checks the safety of aot-initialized
1971 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
1972 return;
1973 } else {
1974 // In this case, the special subgraph should contain a few specific types
1975 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
1976 int num = klasses->length();
1977 for (int i = 0; i < num; i++) {
1978 Klass* subgraph_k = klasses->at(i);
1979 Symbol* name = subgraph_k->name();
1980 if (subgraph_k->is_instance_klass() &&
1981 name != vmSymbols::java_lang_Class() &&
1982 name != vmSymbols::java_lang_String() &&
1983 name != vmSymbols::java_lang_ArithmeticException() &&
1984 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1985 name != vmSymbols::java_lang_ArrayStoreException() &&
1986 name != vmSymbols::java_lang_ClassCastException() &&
1987 name != vmSymbols::java_lang_InternalError() &&
1988 name != vmSymbols::java_lang_NullPointerException()) {
1989 ResourceMark rm;
1990 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
1991 }
1992 }
1993 }
1994 }
1995
1996 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
1997 HeapShared::PendingOop HeapShared::_object_being_archived;
1998 int HeapShared::_num_new_walked_objs;
1999 int HeapShared::_num_new_archived_objs;
2000 int HeapShared::_num_old_recorded_klasses;
2001
2002 int HeapShared::_num_total_subgraph_recordings = 0;
2003 int HeapShared::_num_total_walked_objs = 0;
2004 int HeapShared::_num_total_archived_objs = 0;
2005 int HeapShared::_num_total_recorded_klasses = 0;
2006 int HeapShared::_num_total_verifications = 0;
2007
2008 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2009 return _seen_objects_table->get(obj) != nullptr;
2010 }
2011
2012 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2013 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2014 _seen_objects_table->put_when_absent(obj, true);
2015 _seen_objects_table->maybe_grow();
2016 ++ _num_new_walked_objs;
2017 }
2018
2019 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2020 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2021 init_subgraph_info(k, is_full_module_graph);
2022 init_seen_objects_table();
2023 _num_new_walked_objs = 0;
2024 _num_new_archived_objs = 0;
2025 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2026 }
2027
2028 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2029 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2030 _num_old_recorded_klasses;
2031 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2032 "walked %d objs, archived %d new objs, recorded %d classes",
2033 class_name, _num_new_walked_objs, _num_new_archived_objs,
2034 num_new_recorded_klasses);
2035
2036 delete_seen_objects_table();
2037
2038 _num_total_subgraph_recordings ++;
2039 _num_total_walked_objs += _num_new_walked_objs;
2040 _num_total_archived_objs += _num_new_archived_objs;
2041 _num_total_recorded_klasses += num_new_recorded_klasses;
2042 }
2043
2044 class ArchivableStaticFieldFinder: public FieldClosure {
2045 InstanceKlass* _ik;
2046 Symbol* _field_name;
2047 bool _found;
2048 int _offset;
2049 public:
2050 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2051 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2052
2053 virtual void do_field(fieldDescriptor* fd) {
2054 if (fd->name() == _field_name) {
2055 assert(!_found, "fields can never be overloaded");
2056 if (is_reference_type(fd->field_type())) {
2057 _found = true;
2058 _offset = fd->offset();
2059 }
2060 }
2061 }
2062 bool found() { return _found; }
2063 int offset() { return _offset; }
2064 };
2065
2066 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2067 TRAPS) {
2068 for (int i = 0; fields[i].valid(); i++) {
2069 ArchivableStaticFieldInfo* info = &fields[i];
2070 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2071 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2072 ResourceMark rm; // for stringStream::as_string() etc.
2073
2074 #ifndef PRODUCT
2075 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2076 const char* test_class_name = ArchiveHeapTestClass;
2077 #else
2078 bool is_test_class = false;
2079 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2080 #endif
2081
2082 if (is_test_class) {
2083 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2084 }
2085
2086 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2087 if (HAS_PENDING_EXCEPTION) {
2088 CLEAR_PENDING_EXCEPTION;
2089 stringStream st;
2090 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2091 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2092 }
2093
2094 if (!k->is_instance_klass()) {
2095 stringStream st;
2096 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2097 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2098 }
2099
2100 InstanceKlass* ik = InstanceKlass::cast(k);
2101 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2102 "Only support boot classes");
2103
2104 if (is_test_class) {
2105 if (ik->module()->is_named()) {
2106 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2107 // core-lib classes. You need to at least append to the bootclasspath.
2108 stringStream st;
2109 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2110 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2111 }
2112
2113 if (ik->package() != nullptr) {
2114 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2115 stringStream st;
2116 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2117 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2118 }
2119 } else {
2120 if (ik->module()->name() != vmSymbols::java_base()) {
2121 // We don't want to deal with cases when a module is unavailable at runtime.
2122 // FUTURE -- load from archived heap only when module graph has not changed
2123 // between dump and runtime.
2124 stringStream st;
2125 st.print("%s is not in java.base module", info->klass_name);
2126 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2127 }
2128 }
2129
2130 if (is_test_class) {
2131 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2132 }
2133 ik->initialize(CHECK);
2134
2135 ArchivableStaticFieldFinder finder(ik, field_name);
2136 ik->do_local_static_fields(&finder);
2137 if (!finder.found()) {
2138 stringStream st;
2139 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2140 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2141 }
2142
2143 info->klass = ik;
2144 info->offset = finder.offset();
2145 }
2146 }
2147
2148 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2149 assert(CDSConfig::is_dumping_heap(), "must be");
2150 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2151 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2152 if (CDSConfig::is_dumping_full_module_graph()) {
2153 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2154 }
2155 }
2156
2157 #ifndef PRODUCT
2158 void HeapShared::setup_test_class(const char* test_class_name) {
2159 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2160 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2161 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2162 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2163
2164 if (test_class_name != nullptr) {
2165 p[num_slots - 2].klass_name = test_class_name;
2166 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2167 }
2168 }
2169
2170 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2171 // during runtime. This may be called before the module system is initialized so
2172 // we cannot rely on InstanceKlass::module(), etc.
2173 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2174 if (_test_class != nullptr) {
2175 if (ik == _test_class) {
2176 return true;
2177 }
2178 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2179 if (klasses == nullptr) {
2180 return false;
2181 }
2182
2183 for (int i = 0; i < klasses->length(); i++) {
2184 Klass* k = klasses->at(i);
2185 if (k == ik) {
2186 Symbol* name;
2187 if (k->is_instance_klass()) {
2188 name = InstanceKlass::cast(k)->name();
2189 } else if (k->is_objArray_klass()) {
2190 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2191 if (!bk->is_instance_klass()) {
2192 return false;
2193 }
2194 name = bk->name();
2195 } else {
2196 return false;
2197 }
2198
2199 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2200 // to be:
2201 // (A) java.base classes (which must not be in the unnamed module)
2202 // (B) test classes which must be in the unnamed package of the unnamed module.
2203 // So if we see a '/' character in the class name, it must be in (A);
2204 // otherwise it must be in (B).
2205 if (name->index_of_at(0, "/", 1) >= 0) {
2206 return false; // (A)
2207 }
2208
2209 return true; // (B)
2210 }
2211 }
2212 }
2213
2214 return false;
2215 }
2216
2217 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2218 Klass* k = _test_class;
2219 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2220 JavaThread* THREAD = current;
2221 ExceptionMark em(THREAD);
2222 const ArchivedKlassSubGraphInfoRecord* record =
2223 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2224
2225 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2226 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2227 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2228 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2229 if (record != nullptr) {
2230 init_archived_fields_for(k, record);
2231 }
2232 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2233 }
2234 }
2235 #endif
2236
2237 void HeapShared::init_for_dumping(TRAPS) {
2238 if (CDSConfig::is_dumping_heap()) {
2239 setup_test_class(ArchiveHeapTestClass);
2240 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2241 init_subgraph_entry_fields(CHECK);
2242 }
2243 }
2244
2245 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2246 bool is_full_module_graph) {
2247 _num_total_subgraph_recordings = 0;
2248 _num_total_walked_objs = 0;
2249 _num_total_archived_objs = 0;
2250 _num_total_recorded_klasses = 0;
2251 _num_total_verifications = 0;
2252
2253 // For each class X that has one or more archived fields:
2254 // [1] Dump the subgraph of each archived field
2255 // [2] Create a list of all the class of the objects that can be reached
2256 // by any of these static fields.
2257 // At runtime, these classes are initialized before X's archived fields
2258 // are restored by HeapShared::initialize_from_archived_subgraph().
2259 for (int i = 0; fields[i].valid(); ) {
2260 ArchivableStaticFieldInfo* info = &fields[i];
2261 const char* klass_name = info->klass_name;
2262 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2263
2264 ContextMark cm(klass_name);
2265 // If you have specified consecutive fields of the same klass in
2266 // fields[], these will be archived in the same
2267 // {start_recording_subgraph ... done_recording_subgraph} pass to
2268 // save time.
2269 for (; fields[i].valid(); i++) {
2270 ArchivableStaticFieldInfo* f = &fields[i];
2271 if (f->klass_name != klass_name) {
2272 break;
2273 }
2274
2275 ContextMark cm(f->field_name);
2276 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2277 f->offset, f->field_name);
2278 }
2279 done_recording_subgraph(info->klass, klass_name);
2280 }
2281
2282 log_info(aot, heap)("Archived subgraph records = %d",
2283 _num_total_subgraph_recordings);
2284 log_info(aot, heap)(" Walked %d objects", _num_total_walked_objs);
2285 log_info(aot, heap)(" Archived %d objects", _num_total_archived_objs);
2286 log_info(aot, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2287
2288 #ifndef PRODUCT
2289 for (int i = 0; fields[i].valid(); i++) {
2290 ArchivableStaticFieldInfo* f = &fields[i];
2291 verify_subgraph_from_static_field(f->klass, f->offset);
2292 }
2293 log_info(aot, heap)(" Verified %d references", _num_total_verifications);
2294 #endif
2295 }
2296
2297 // Keep track of the contents of the archived interned string table. This table
2298 // is used only by CDSHeapVerifier.
2299 void HeapShared::add_to_dumped_interned_strings(oop string) {
2300 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2301 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2302 bool created;
2303 _dumped_interned_strings->put_if_absent(string, true, &created);
2304 if (created) {
2305 // Prevent string deduplication from changing the value field to
2306 // something not in the archive.
2307 java_lang_String::set_deduplication_forbidden(string);
2308 _dumped_interned_strings->maybe_grow();
2309 }
2310 }
2311
2312 bool HeapShared::is_dumped_interned_string(oop o) {
2313 return _dumped_interned_strings->get(o) != nullptr;
2314 }
2315
2316 void HeapShared::debug_trace() {
2317 ResourceMark rm;
2318 oop referrer = _object_being_archived.referrer();
2319 if (referrer != nullptr) {
2320 LogStream ls(Log(aot, heap)::error());
2321 ls.print_cr("Reference trace");
2322 CDSHeapVerifier::trace_to_root(&ls, referrer);
2323 }
2324 }
2325
2326 #ifndef PRODUCT
2327 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2328 // region. This way we can quickly relocate all the pointers without using
2329 // BasicOopIterateClosure at runtime.
2330 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2331 void* _start;
2332 BitMap *_oopmap;
2333 int _num_total_oops;
2334 int _num_null_oops;
2335 public:
2336 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2337 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2338
2339 virtual void do_oop(narrowOop* p) {
2340 assert(UseCompressedOops, "sanity");
2341 _num_total_oops ++;
2342 narrowOop v = *p;
2343 if (!CompressedOops::is_null(v)) {
2344 size_t idx = p - (narrowOop*)_start;
2345 _oopmap->set_bit(idx);
2346 } else {
2347 _num_null_oops ++;
2348 }
2349 }
2350 virtual void do_oop(oop* p) {
2351 assert(!UseCompressedOops, "sanity");
2352 _num_total_oops ++;
2353 if ((*p) != nullptr) {
2354 size_t idx = p - (oop*)_start;
2355 _oopmap->set_bit(idx);
2356 } else {
2357 _num_null_oops ++;
2358 }
2359 }
2360 int num_total_oops() const { return _num_total_oops; }
2361 int num_null_oops() const { return _num_null_oops; }
2362 };
2363 #endif
2364
2365 void HeapShared::count_allocation(size_t size) {
2366 _total_obj_count ++;
2367 _total_obj_size += size;
2368 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2369 if (size <= (size_t(1) << i)) {
2370 _alloc_count[i] ++;
2371 _alloc_size[i] += size;
2372 return;
2373 }
2374 }
2375 }
2376
2377 static double avg_size(size_t size, size_t count) {
2378 double avg = 0;
2379 if (count > 0) {
2380 avg = double(size * HeapWordSize) / double(count);
2381 }
2382 return avg;
2383 }
2384
2385 void HeapShared::print_stats() {
2386 size_t huge_count = _total_obj_count;
2387 size_t huge_size = _total_obj_size;
2388
2389 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2390 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2391 size_t count = _alloc_count[i];
2392 size_t size = _alloc_size[i];
2393 log_info(aot, heap)("%8zu objects are <= %-6zu"
2394 " bytes (total %8zu bytes, avg %8.1f bytes)",
2395 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2396 huge_count -= count;
2397 huge_size -= size;
2398 }
2399
2400 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2401 ", avg %8.1f bytes)",
2402 huge_count, huge_size * HeapWordSize,
2403 avg_size(huge_size, huge_count));
2404 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2405 ", avg %8.1f bytes)",
2406 _total_obj_count, _total_obj_size * HeapWordSize,
2407 avg_size(_total_obj_size, _total_obj_count));
2408 }
2409
2410 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2411 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2412 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2413 if (k == nullptr) {
2414 return false;
2415 } else {
2416 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2417 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2418 fieldDescriptor fd;
2419 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2420 oop m = k->java_mirror();
2421 oop f = m->obj_field(fd.offset());
2422 if (CompressedOops::is_null(f)) {
2423 return false;
2424 }
2425 } else {
2426 return false;
2427 }
2428 }
2429 return true;
2430 }
2431
2432 #endif // INCLUDE_CDS_JAVA_HEAP